Thin and high-pitch laser-etched mesh manufacturing and bulking"

(INFN Bari, CEA Saclay, CERN)

RD51 Common Projects

V. Berardi, P. Colas, Rui de OliveiraWith help from D. Attié, M. Kebbiri, O. Pizzirusso, W. Wang,

and A.Ancona, T. Sibillano, F. Di Niso (CNR)

WG 1 – New techniques

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Project started Feb. 15, 2012 for an initial duration of one year.

Sharing of the tasks : Bari : improve laser punching techniqueCEA Saclay : test of meshes, gain, ion back-flowCERN: bulking with various meshes

Funding : 19 000 CHF (8 000 Bari, 5000 Saclay, 6000 CERN)

Motivation : extend the bulk process (so far using only woven meshes) to thinner and higher-pitch meshes, to optimize ion back-flow, electron collection, and resolution. Favor non-magnetic materials

Two paths : laser punching and bulking of new electroformed meshes

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Progress in laser-etched meshes

First attempt in February using double-layer of copper -> no signal. The holes were not open. Very difficult to ‘peal’ the mesh.

Second attempt (10x10 mm² meshes received in Saclay after Stony Brook) : transparency OK. To be tested in gas.

With the present laser: 10 holes/s.A factor of 5 could be gained.

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Cost for 8 6’’ x 6’’ copper meshes : 2529 euro wo tax. Payed half-half by Saclay and RD51.

Woven meshes are typically 380-450 lpi

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First thin-mesh bulk

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Performances tested at Saclay

260 280 300 320 340 360 380100

1000

10000

Ar95%:iso5% Gap:64µm

Vmesh(V)

Gain

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Financial reportCurrency: CHF Bari CEA Saclay CERN

Available (Own) 4000 2500 3000

Available (RD51) 4000 2500 3000

Spent (Own) 0 750 (meshes)+500 (test, gas, box…)

750(meshes)+500 (bulking)

Spent (RD51) 0 750 750

In total, only 4 kCHF were spent out of 19. Bari benefited from a huge investment (500 K€ from EU) in the CNR laser lab.

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Conclusions• Recently the common project on meshes

made good progress: First thin-mesh bulk made at CERN.

• New laser-etched meshes ready to be tested• Main goals will be attained within initial

schedule (before February 15, 2013)

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